Replacement heart valve systems and methods

ABSTRACT

Systems and methods for replacing a native heart valve. An anchor comprises multiple coils adapted to support a heart valve prosthesis. At least one of the coils is normally at a first diameter, and is expandable to a second, larger diameter upon application of radial outward force from within the anchor. An expansible heart valve prosthesis is provided and is configured to be delivered into the anchor and expanded inside the multiple coils. This moves at least one coil from the first diameter to the second diameter while securing the anchor and the heart valve prosthesis relative to each other. The system further includes a seal on the anchor that can prevent at least some blood leakage after implantation of the heart valve prosthesis in the helical anchor. Additional apparatus and methods are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/912,067, filed Feb. 12, 2016, which is a U.S. national phaseapplication of PCT patent application PCT/US2014/051095, filed Aug. 14,2014, which claims the priority of U.S. Provisional Application Ser. No.61/865,657, filed Aug. 14, 2013; U.S. Provisional Application Ser. No.61/942,300, filed Feb. 20, 2014; and U.S. Provisional Application Ser.No. 61/943,125, filed Feb. 21, 2014, the disclosures of each of theforegoing are hereby incorporated by reference herein.

TECHNICAL FIELD

The present invention generally relates to medical procedures anddevices pertaining to heart valves such as replacement techniques andapparatus. More specifically, the invention relates to the replacementof heart valves having various malformations and dysfunctions.

BACKGROUND

Complications of the mitral valve, which controls the flow of blood fromthe left atrium into the left ventricle of the human heart, have beenknown to cause fatal heart failure. In the developed world, one of themost common forms of valvular heart disease is mitral valve leak, alsoknown as mitral regurgitation, which is characterized by the abnormalleaking of blood from the left ventricle through the mitral valve andback into the left atrium. This occurs most commonly due to ischemicheart disease when the leaflets of the mitral valve no longer meet orclose properly after multiple infarctions, idiopathic and hypertensivecardiomyopathies where the left ventricle enlarges, and with leaflet andchordal abnormalities, such as those caused by a degenerative disease.

In addition to mitral regurgitation, mitral narrowing or stenosis ismost frequently the result of rheumatic disease. While this has beenvirtually eliminated in developed countries, it is still common whereliving standards are not as high.

Similar to complications of the mitral valve are complications of theaortic valve, which controls the flow of blood from the left ventricleinto the aorta. For example, many older patients develop aortic valvestenosis. Historically, the traditional treatment had been valvereplacement by a large open heart procedure. The procedure takes aconsiderable amount of time for recovery since it is so highly invasive.Fortunately, in the last decade, great advances have been made inreplacing this open heart surgery procedure with a catheter procedurethat can be performed quickly without surgical incisions or the need fora heart-lung machine to support the circulation while the heart isstopped. Using catheters, valves are mounted on stents or stent-likestructures, which are compressed and delivered through blood vessels tothe heart. The stents are then expanded and the valves begin tofunction. The diseased valve is not removed, but instead it is crushedor deformed by the stent which contains the new valve. The deformedtissue serves to help anchor the new prosthetic valve.

Delivery of the valves can be accomplished from arteries which can beeasily accessed in a patient. Most commonly this is done from the groinwhere the femoral and iliac arteries can be cannulated. The shoulderregion is also used, where the subclavian and axillary arteries can alsobe accessed. Recovery from this procedure is remarkably quick.

Not all patients can be served with a pure catheter procedure. In somecases the arteries are too small to allow passage of catheters to theheart, or the arteries are too diseased or tortuous. In these cases,surgeons can make a small chest incision (thoractomy) and then placethese catheter-based devices directly into the heart. Typically, a pursestring suture is made in the apex of the left ventricle and the deliverysystem is placed through the apex of the heart. The valve is thendelivered into its final position. These delivery systems can also beused to access the aortic valve from the aorta itself. Some surgeonsintroduce the aortic valve delivery system directly in the aorta at thetime of open surgery. The valves vary considerably. There is a mountingstructure that is often a form of stent. Prosthetic leaflets are carriedinside the stent on mounting and retention structure. Typically, theseleaflets are made from biologic material that is used in traditionalsurgical valves. The valve can be actual heart valve tissue from ananimal or more often the leaflets are made from pericardial tissue fromcows, pigs or horses. These leaflets are treated to reduce theirimmunogenicity and improve their durability. Many tissue processingtechniques have been developed for this purpose. In the future,biologically engineered tissue may be used or polymers or othernon-biologic materials may be used for valve leaflets. All of these canbe incorporated into the inventions described in this disclosure.

There are, in fact, more patients with mitral valve disease than aorticvalve disease. In the course of the last decade, many companies havebeen successful in creating catheter or minimally invasive implantableaortic valves, but implantation of a mitral valve is more difficult andto date there has been no good solution. Patients would be benefited byimplanting a device by a surgical procedure employing a small incisionor by a catheter implantation such as from the groin. From the patient'spoint of view, the catheter procedure is very attractive. At this timethere is no commercially available way to replace the mitral valve witha catheter procedure. Many patients who require mitral valve replacementare elderly and an open heart procedure is painful, risky and takes timefor recovery. Some patients are not even candidates for surgery due toadvanced age and frailty. Therefore, there exists a particular need fora remotely placed mitral valve replacement device.

While previously, it was thought that mitral valve replacement ratherthan valve repair was associated with a more negative long-termprognosis for patients with mitral valve disease, this belief has comeinto question. It is now believed that the outcome for patients withmitral valve leak or regurgitation is almost equal whether the valve isrepaired or replaced. Furthermore, the durability of a mitral valvesurgical repair is now under question. Many patients, who have undergonerepair, redevelop a leak over several years. As many of these areelderly, a repeat intervention in an older patient is not welcomed bythe patient or the physicians.

The most prominent obstacle for catheter mitral valve replacement isretaining the valve in position. The mitral valve is subject to a largecyclic load. The pressure in the left ventricle is close to zero beforecontraction and then rises to the systolic pressure (or higher if thereis aortic stenosis) and this can be very high if the patient hassystolic hypertension. Often the load on the valve is 150 mm Hg or more.Since the heart is moving as it beats, the movement and the load cancombine to dislodge a valve. Also, the movement and rhythmic load canfatigue materials leading to fractures of the materials. Thus, there isa major problem associated with anchoring a valve.

Another problem with creating a catheter delivered mitral valvereplacement is size. The implant must have strong retention and leakavoidance features and it must contain a valve. Separate prostheses maycontribute to solving this problem, by placing an anchor or dock firstand then implanting the valve second. However, in this situation, thepatient must remain stable between implantation of the anchor or dockand implantation of the valve. If the patient's native mitral valve isrendered non-functional by the anchor or dock, then the patient mayquickly become unstable and the operator may be forced to hastilyimplant the new valve or possibly stabilize the patient by removing theanchor or dock and abandoning the procedure.

Another problem with mitral replacement is leak around the valve, orparavalvular leak. If a good seal is not established around the valve,blood can leak back into the left atrium. This places extra load on theheart and can damage the blood as it travels in jets through sites ofleaks. Hemolysis or breakdown of red blood cells is a frequentcomplication if this occurs. Paravalvular leak was one of the commonproblems encountered when the aortic valve was first implanted on acatheter. During surgical replacement, a surgeon has a major advantagewhen replacing the valve as he or she can see a gap outside the valvesuture line and prevent or repair it. With catheter insertion, this isnot possible. Furthermore, large leaks may reduce a patient's survivaland may cause symptoms that restrict mobility and make the patientuncomfortable (e.g., short of breathe, edematous, fatigued). Therefore,devices, systems, and methods which relate to mitral valve replacementshould also incorporate means to prevent and repair leaks around thereplacement valve.

A patient's mitral valve annulus can also be quite large. When companiesdevelop surgical replacement valves, this problem is solved byrestricting the number of sizes of the actual valve produced and thenadding more fabric cuff around the margin of the valve to increase thevalve size. For example, a patient may have a 45 mm valve annulus. Inthis case, the actual prosthetic valve diameter may be 30 mm and thedifference is made up by adding a larger band of fabric cuff materialaround the prosthetic valve. However, in catheter procedures, addingmore material to a prosthetic valve is problematic since the materialmust be condensed and retained by small delivery systems. Often, thismethod is very difficult and impractical, so alternative solutions arenecessary.

Since numerous valves have been developed for the aortic position, it isdesirable to avoid repeating valve development and to take advantage ofexisting valves. These valves have been very expensive to develop andbring to market, so extending their application can save considerableamounts of time and money. It would be useful then to create a mitralanchor or docking station for such a valve. An existing valve developedfor the aortic position, perhaps with some modification, could then beimplanted in the docking station. Some previously developed valves mayfit well with no modification, such as the Edwards Sapien™ valve.Others, such as the Corevalve™ may be implantable but require somemodification for an optimal engagement with the anchor and fit insidethe heart.

A number of further complications may arise from a poorly retained orpoorly positioned mitral valve replacement prosthesis. Namely, a valvecan be dislodged into the atrium or ventricle, which could be fatal fora patient. Prior prosthetic anchors have reduced the risk ofdislodgement by puncturing tissue to retain the prosthesis. However,this is a risky maneuver since the penetration must be accomplished by asharp object at a long distance, leading to a risk of perforation of theheart and patient injury.

Orientation of the mitral prosthesis is also important. The valve mustallow blood to flow easily from the atrium to the ventricle. Aprosthesis that enters at an angle may lead to poor flow, obstruction ofthe flow by the wall of the heart or a leaflet and a poor hemodynamicresult. Repeated contraction against the ventricular wall can also leadto rupture of the back wall of the heart and sudden death of thepatient.

With surgical mitral valve repair or replacement, sometimes the anteriorleaflet of the mitral valve leaflet is pushed into the area of the leftventricular outflow and this leads to poor left ventricular emptying.This syndrome is known as left ventricular tract outflow obstruction.The replacement valve itself can cause left ventricular outflow tractobstruction if it is situated close to the aortic valve.

Yet another obstacle faced when implanting a replacement mitral valve isthe need for the patient's native mitral valve to continue to functionregularly during placement of the prosthesis so that the patient canremain stable without the need for a heart-lung machine to supportcirculation.

In addition, it is desirable to provide devices and methods that can beutilized in a variety of implantation approaches. Depending on aparticular patient's anatomy and clinical situation, a medicalprofessional may wish to make a determination regarding the optimalmethod of implantation, such as inserting a replacement valve directlyinto the heart in an open procedure (open heart surgery or a minimallyinvasive surgery) or inserting a replacement valve from veins and viaarteries in a closed procedure (such as a catheter-based implantation).It is preferable to allow a medical professional a plurality ofimplantation options to choose from. For example, a medical professionalmay wish to insert a replacement valve either from the ventricle or fromthe atrial side of the mitral valve.

Therefore, the present invention provides devices and methods thataddress these and other challenges in the art.

SUMMARY

In one illustrative embodiment, the invention provides a system forreplacing a native heart valve including an expansible helical anchorformed as multiple coils adapted to support a heart valve prosthesis. Atleast one of the coils is normally at a first diameter, and isexpandable to a second, larger diameter upon application of radialoutward force from within the helical anchor. A gap is defined betweenadjacent coils sufficient to prevent engagement by at least one of theadjacent coils with the native heart valve. An expansible heart valveprosthesis is provided and is configured to be delivered into thehelical anchor and expanded inside the multiple coils into engagementwith the at least one coil. This moves at least that coil from the firstdiameter to the second diameter while securing the helical anchor andthe heart valve prosthesis together. The system further includes a sealon the expansible heart valve prosthesis configured to engage thehelical anchor and prevent blood leakage past the heart valve prosthesisafter implantation of the heart valve prosthesis in the helical anchor.

The system may include one or more additional aspects. For example, thehelical anchor may include another coil that moves from a largerdiameter to a smaller diameter as the heart valve prosthesis is expandedinside the multiple coils. The seal may take many alternative forms. Forexample, the seal can include portions extending between adjacent coilsfor preventing blood leakage through the helical anchor and past theheart valve prosthesis. The seal may be comprised of many differentalternative materials. The seal may further comprise a membrane or panelextending between at least two coils of the helical anchor afterimplantation of the heart valve prosthesis in the helical anchor. Forexample, one example is a biologic material. The helical anchor mayfurther comprise a shape memory material. The heart valve prosthesisincludes a blood inflow end and a blood outflow end and at least one ofthe ends may be unflared and generally cylindrical in shape. In anillustrative embodiment, the blood outflow end is flared radiallyoutward and includes a bumper for preventing damage to tissue structurein the heart after implantation. The gap may be formed by a coil portionof the helical anchor that extends non-parallel to adjacent coilportions of the helical anchor.

In another illustrative embodiment, a system is provided as generallydescribed above, except that the seal is alternatively or additionallycarried on the helical anchor instead of being carried on the heartvalve prosthesis. Any other features as described or incorporated hereinmay be included.

In another illustrative embodiment, a system for docking a heart valveprosthesis includes a helical anchor formed as multiple coils adapted tosupport a heart valve prosthesis with coil portions positioned aboveand/or below the heart valve annulus. An outer, flexible and helicaltube carries the coils of the helical anchor to form an assembly. Ahelical delivery tool carries the assembly and is adapted to be rotatedinto position through a native heart valve. Additional or optionalfeatures may be provided. For example, a heart valve prosthesis may beexpanded inside the multiple coils. The outer tube may be formed from alow friction material adapted to slide off of the multiple coils of thehelical anchor after rotating into position through the native heartvalve. The outer tube may be secured to the helical delivery tool withsuture or by any other method. The helical delivery tool may formed witha plurality of coils, and the outer tube may further be secured to thedistal end. The distal end may further comprise a bullet or taperedshape to assist with delivery. The distal end can further comprise aresilient element, and the distal ends of the outer tube and the helicaldelivery tube are secured to the resilient element.

In another illustrative embodiment, a system for replacing a nativeheart valve includes a helical anchor formed as multiple coils adaptedto support a heart valve prosthesis at the native heart valve. Anexpansible heart valve prosthesis is provided in this system and iscapable of being delivered into the helical anchor and expanded insidethe multiple coils into engagement with the at least one coil to securethe helical anchor and the heart valve prosthesis together. A guidestructure on the expansible heart valve prosthesis is configured toguide the helical anchor into position as the helical anchor is extrudedfrom a helical anchor delivery catheter.

The guide structure may further comprise an opening within a portion ofthe expansible heart valve prosthesis, such as an opening in a loop, atube or simply an opening in the stent structure of the expansible heartvalve prosthesis, for example. The opening may be configured to receivea helical anchor delivery catheter that carries the helical anchorduring the implantation procedure. The opening may be located on an armof the expansible heart valve prosthesis and the prosthesis may furthercomprise a plurality of arms configured to engage beneath the nativeheart valve. The guide structure may further comprise a tubular arm ofthe expansible heart valve prosthesis.

In another illustrative embodiment, a system for docking a mitral valveprosthesis and replacing a native mitral valve is provided and includesa coil guide catheter and a helical anchor adapted to be received in anddelivered from the coil guide catheter. The helical anchor is formed asmultiple coils having a coiled configuration after being delivered fromthe coil guide catheter and adapted to support the mitral valveprosthesis upon being fully delivered from the coil guide catheter andimplanted at the native mitral valve. The system further includes atissue gathering catheter including loop structure configured to bedeployed to surround and gather the native chordea tendinae for allowingeasier direction of the helical anchor in the left ventricle.

In another illustrative embodiment, an anchor for docking a heart valveprosthesis includes an upper helical coil portion, a lower helical coilportion, and a fastener securing the upper helical coil portion to thelower helical coil portion.

In another illustrative embodiment, a method of implanting a heart valveprosthesis in the heart of a patient includes holding a helical anchorin the form of multiple coils within an outer, flexible tube. Theassembly of the outer, flexible tube and the helical anchor is securedto a helical delivery tool. The helical delivery tool is rotatedadjacent to a native heart valve of the patient to position the assemblyon either or both sides of the native heart valve. The assembly isremoved from the helical delivery tool, and the outer tube is removedfrom the helical anchor. The heart valve prosthesis is then implantedwithin the helical anchor.

Securing the assembly may further comprise positioning coils of theassembly generally along adjacent coils of the helical delivery tool.Removing the outer tube may further comprise holding the helical anchorwith a pusher element, and pulling the outer tube off the helicalanchor.

In another illustrative embodiment, a method of implanting an expansibleheart valve prosthesis in the heart of a patient includes delivering anexpansible helical anchor in the form of multiple coils proximate thenative heart valve. The expansible heart valve prosthesis is positionedwithin the multiple coils of the expansible helical anchor with theexpansible heart valve prosthesis and the expansible helical anchor inunexpanded states. The expansible heart valve prosthesis is expandedagainst the expansible helical anchor thereby expanding the expansibleheart valve prosthesis while securing the expansible heart valveprosthesis to the expansible helical anchor. A seal is carried on thehelical anchor and/or on the heart valve prosthesis and extends betweenat least two adjacent coils for preventing blood leakage through thehelical anchor and past the heart valve prosthesis.

In another illustrative embodiment, a method of implanting an expansibleheart valve prosthesis to replace a native heart valve of a patientincludes delivering a helical anchor in the form of multiple coilsproximate the native heart valve. The expansible heart valve prosthesisis delivered proximate the native heart valve. The helical anchor isguided generally around a periphery of the expansible heart valveprosthesis using guide structure carried on the expansible heart valveprosthesis. The expansible heart valve prosthesis is expanded againstthe helical anchor. As discussed above, the guide structure may takemany different forms.

In another illustrative embodiment, a method of implanting a helicalanchor for docking a mitral heart valve prosthesis in a patient includesgathering the chordea tendinae using a tissue gathering catheter. Ahelical anchor is then delivered in the form of multiple coils proximatea native heart valve and around the gathered chordae tendinae.

In another illustrative embodiment, a method of implanting a helicalanchor for docking a heart valve prosthesis in a patient includesdelivering an upper helical anchor portion comprised of upper coils to aposition above a native heart valve, and delivering a lower helicalanchor portion comprised of lower coils to a position below the nativeheart valve. The upper and lower helical anchor portions are securedtogether with a fastener either before or after delivery of each helicalanchor portion.

In another illustrative embodiment, a system for replacing a nativeheart valve is provided and includes an expansible helical anchor formedas multiple coils adapted to support a heart valve prosthesis. At leastone of the coils is normally at a first diameter, and is expandable to asecond, larger diameter upon application of radial outward force fromwithin the helical anchor. A gap is defined between adjacent coilssufficient to prevent engagement by at least one of the adjacent coilswith the native heart valve. An expansible heart valve prosthesis isprovided and is capable of being delivered into the helical anchor andexpanded inside the multiple coils into engagement with the at least onecoil. In this manner, the expansible coil moves from the first diameterto the second diameter while securing the helical anchor and the heartvalve prosthesis together. The expansible heart valve prosthesisincludes an inflow end and an outflow end. The inflow end is unflaredand generally cylindrical, while the outflow end is flared in a radiallyoutward direction.

Various additional advantages, methods, devices, systems and featureswill become more readily apparent to those of ordinary skill in the artupon review of the following detailed description of the illustrativeembodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically illustrating the introductionof a helical anchor to the position of the native mitral valve.

FIG. 2A is an enlarged cross-sectional view illustrating an initialportion of the procedure shown in FIG. 1, but with use of a deflectablecatheter.

FIG. 2B is a cross-sectional view of the heart similar to FIG. 2A, butillustrating deflection of the delivery catheter and introduction of thehelical anchor underneath the native mitral valve.

FIGS. 3A and 3B are enlarged elevational views illustrating the distalend of the delivery catheter and its deflecting capability.

FIGS. 4A and 4B are respective top views of FIGS. 3A and 3B.

FIG. 5A is a side elevational view similar to FIG. 3B, but illustratingthe use of a wire within the delivery catheter used for deflecting orsteering the distal end.

FIG. 5B is a cross-sectional, top view of the delivery catheter shown inFIG. 5A.

FIG. 6A is a perspective view showing the combination of a helicalanchor and an outer tube used for assisting with the delivery of thehelical anchor to the native mitral valve location.

FIG. 6B is a perspective view of the helical anchor within the outertube shown in FIG. 6A.

FIG. 7A is an elevational view showing a helical delivery tool used todeliver the assembly of FIG. 6B to the native mitral valve location.

FIG. 7B is a perspective view illustrating the attachment of theassembly shown in FIG. 6B to the helical delivery tool shown in FIG. 7A.

FIG. 8A is a perspective view showing the heart in cross section and thehelical delivery tool being used to implant the assembly of FIG. 6B.

FIGS. 8B through 8E are perspective views showing further steps in themethod of implantation.

FIG. 8F is a perspective view showing the implanted helical anchor.

FIG. 8G is a cross-sectional view showing a replacement heart valve,such as a stent mounted valve, within the implanted helical anchor.

FIG. 9 is a perspective view illustrating another illustrativeembodiment of a tool and assembly for implanting a helical anchor.

FIG. 10 is a partially cross-section top view showing the assembly ofFIG. 9.

FIG. 11A is a cross-sectional view of the distal end of an alternativeembodiment of a helical anchor and delivery catheter.

FIG. 11B is a perspective view of the distal end of another embodimentof a helical anchor and delivery catheter.

FIG. 12 is a cross-sectional view of an implanted replacement stentmounted valve and helical anchor at a native mitral valve locationaccording to another illustrative embodiment.

FIG. 13 is an enlarged cross-sectional view showing another illustrativeembodiment of a stent mounted replacement heart valve.

FIG. 13A is an enlarged cross-sectional view showing a non-flaredembodiment of the outflow end of the replacement heart valve shown inFIG. 13.

FIG. 14A is a cross-sectional view illustrating another illustrativeembodiment of a replacement heart valve secured within a helical anchor.

FIG. 14B is an enlarged cross-sectional view of the replacement valveshown in FIG. 14A.

FIG. 15A is a schematic view showing a heart in cross section andinitial introduction of a delivery catheter to the mitral valvelocation.

FIG. 15B is an enlarged cross-sectional view of the heart showing afurther step in the introduction of a stent mounted replacement heartvalve together with a helical anchor.

FIGS. 15C through 15F are views similar to FIG. 15B, but illustratingprogressively further steps in the method of introducing the helicalanchor and stent mounted replacement heart valve at the native mitralvalve location.

FIGS. 16A and 16B are schematic elevational views showing thesimultaneous deployment of a stent mounted replacement heart valve and ahelical anchor using an arm with a loop on the stent valve.

FIGS. 17A and 17B are similar to FIGS. 16A and 16B, but illustrateanother embodiment.

FIGS. 18A, 18B and 18C are views similar to FIGS. 16A and 16B, however,these views progressively illustrate another embodiment of a method fordeploying a helical anchor and a stent mounted replacement heart valve.

FIG. 19A is a side elevational view of a helical anchor constructed inaccordance with another illustrative embodiment.

FIG. 19B is a cross-sectional view taken along line 19B-19B of FIG. 19A.

FIG. 20 is a schematic perspective view illustrating another alternativesystem for delivering a helical anchor.

FIG. 21A is a schematic perspective view illustrating the initialdelivery of an alternative helical anchor.

FIG. 21B is a schematic perspective view of the fully delivered helicalanchor of FIG. 21A.

FIG. 22A is a cross-sectional view showing another illustrativeembodiment of a helical anchor including a seal.

FIG. 22B is a cross-sectional view similar to FIG. 22A, but showing thehelical anchor implanted at the location of a native mitral valve and anexpandable stent mounted replacement valve held within the helicalanchor.

FIG. 23A is a schematic elevational view showing another illustrativeembodiment of a helical anchor before expansion with a balloon catheter.

FIG. 23B is an elevational view similar to FIG. 23A, but illustratingthe helical anchor during expansion by the balloon catheter.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

It will be appreciated that like reference numerals throughout thisdescription and the drawings refer generally to like elements ofstructure and function. The differences between embodiments will beapparent from the drawings and/or from the description and/or the use ofdifferent reference numerals in different figures. For clarity andconciseness, description of like elements will not be repeatedthroughout the description.

Referring first to FIG. 1 in conjunction with FIGS. 2A and 2B, aspreviously discussed in Applicant's PCT Application Serial No.PCT/US2013/024114, the disclosure of which is fully incorporated byreference herein, a deflectable catheter 10 makes implantation of ahelical anchor 12 much easier. The deflectable tip 10 a of the catheter10 assists with the helical anchor 12 engaging a commissure 14 of thenative mitral valve 16, as shown in FIG. 1. The tip 10 a of the catheter10 may be designed and configured such that it can bend downward towardthe native leaflets 18, 20 of the mitral valve 16. Once the tip 10 a ofthe catheter 10 is placed generally over the commissure 14 as shown inFIG. 2A, the tip or distal end 10 a may be bent downward and it is thenrelatively easy to push or extrude the helical anchor 12 out of thedistal end 10 a and downward through the mitral valve 16 as shown inFIG. 2B.

Now referring to FIGS. 3A, 3B, 4A, 4B, 5A and 5B, the deflectablecatheter, or anchor delivery catheter 10, may be deflectable at manydifferent points or locations. Deflecting the catheter tip 10 a outwardto increase the radius of the delivery catheter tip 10 a can be veryhelpful, as shown in FIGS. 3A, 3B and 4A, 4B which show the “before” and“after” effects of deflecting the distal end 10 a. Deflecting thecatheter 10 in this way will give the helical anchor 12 a largerdiameter starting turn or coil 22. As an example, this turn or coil 22of the helical anchor 12 may normally be 25 mm but operating the distalend 10 a of the catheter 10 in this manner can enlarge the diameter to30 mm. Opening up the first turn or coil 22 of the helical anchor 12 inthis way would help the helical anchor 12 capture all chordae 24 andleaflets 18, 20 as the helical anchor 12 is introduced as generallydiscussed above in connection with FIG. 1 and FIGS. 2A and 2B. As thehelical anchor 12 advances, the distal end 10 a of the delivery catheter10 could also deflect inward to help the helical anchor 12 capture allof the chordae 24 at the opposite commissure. Moving the distal end 10 aof the delivery catheter 10 from side to side as the helical anchor 12is essentially screwed or rotated into and through the native mitralvalve 16 is essentially like tracking the delivery catheter 10 with theturn or coil 22. In this case, however, the delivery catheter 10 isstationary as only the tip 10 a is moving with the coils 22.Deflectability of the distal end 10 a in any direction may be achievedby embedding a wire 26 that runs the length of the delivery catheter 10.When the wire 26 is pulled, the delivery catheter tip 10 a deflects anddeforms into various shapes as desired or needed in the procedure.

A procedure will now be described for introducing or implanting ahelical anchor 12 in connection with FIGS. 6A, 6B, 7A, 7B, and 8Athrough 8C. A helical delivery tool 30 including coils 31 is used todeliver the helical anchor 12 which is contained within an outer tube32, for example, formed from a Goretex or other low friction material,such as PTFE. Suture 34 is used to secure the combination or assembly ofthe outer tube 32 and helical anchor 12 in place on the coils 31 of thehelical delivery tool 30. A groove (not shown) may be formed in thehelical tool 30 so that it provides a secure seat for the suture.Additional suture 36 is used to tie the leading end of the outer tube 32through a loop 38 at the end of the helical delivery tool 30. Thehelical delivery tool 30 and outer tube/helical anchor combination 32,12 is turned into the heart 40, through the mitral valve 16 as shown andthe suture 34 is cut, for example, with a scalpel 42 (FIG. 8B). A pairof forceps 44 is used to turn the tool 30 in through the native mitralvalve 16 slightly more and this breaks the suture 36 (FIG. 8C). Thehelical tool 30 is then rotated in an opposite direction and removedfrom the heart 40, leaving the helical anchor 12 combined with the outertube 32 in the heart 40, as shown. A push rod 50 with a cupped end 52 isinserted into the trailing end of the outer tube 32 (FIG. 8D). The outertube 32 is then pulled backwards or rearward leaving the helical anchor12 in place while removing the outer tube 32. Due to the low frictionmaterial of the outer tube 32, it easily slides off of the helicalanchor 12. FIGS. 8F and 8G, respectively, show full implantation of thisembodiment of the helical anchor 12 and a replacement heart valve 60mounted within and firmly against the helical anchor 12. The replacementvalve 60 includes leaflets 62, 64, and a body 66 which may be of anysuitable design, such as an expandable stent design.

In another embodiment shown in FIGS. 9 and 10, a bullet shaped head 70is provided on the helical tool 30. There is a slit 72 on thebullet-shaped head 70 that runs parallel to the helical shaped wire orcoil 22 adjacent to the head 70. The bullet-shaped head 70 is formedfrom resilient, polymer, for example, and the slit 72 opens and closesby way of this resiliency. Again, the outer tube 32 is fixed to thehelical delivery tool 30 with a suture (not shown). The leading end 32 aof the outer tube 32 is inserted into the bullet-shaped head 70, forexample, with forceps 44. In this embodiment, the bullet-shaped head 70provides for easier insertion due to its tapered shape.

FIGS. 11A and 11B show additional illustrative embodiments of thecombination of a delivery catheter 10 with a helical anchor 12 inside,before deployment. The distal tip 10 a of the delivery catheter 10includes a taper which may be gradually tapered as shown in FIG. 11A, ormore rounded as shown in FIG. 11B. In each case, the distal tip 10 aconfiguration allows for smoother, easier delivery to a native mitralvalve location and can maneuver through tissue structure, such as nativetissue, within the heart 40. For example, the distal end 10 a of thedelivery catheter 10 may be directed through the mitral valve 16 and mayneed to encircle the chordae 24 either partially or fully (FIG. 1). Asshown in FIG. 11A, the helical anchor 12 may be constructed with aninternal wire coil 12 a and an external covering or coating 12 b such asfabric, and may include a soft tip 12 c, such as formed from polymer, toavoid damage to heart tissue during delivery and to enable easierdelivery.

FIG. 12 is a cross-sectional view showing an illustrative stent mountedreplacement heart valve or prosthesis 60 at the native mitral valve 16location docked in a helical anchor 12. In this embodiment, a “bumper”structure 80 has been added to the annular edge at the outflow end ofthe valve 60. This bumper structure 80 may be formed, for example, fromfoam 82 covered by a sealing material 84 such as fabric or anothersuitable material or coating. This sealing layer 84 extends upward overan open stent structure 86 of the valve 60 to prevent blood leakage pastthe valve 60 and through the coils 22 of the helical anchor 12.

FIG. 13 is an enlarged view of a replacement heart valve 60 similar tothe valve shown in FIG. 12, but showing radially outward flared inflowand outflow ends.

FIG. 13A is an enlarged sectional view showing a generally cylindricaloutflow end, without a radially outward flare.

FIGS. 14A and 14B illustrate another illustrative embodiment of theinvention including a helical anchor 12 docking or mounting areplacement stent valve 60 and including biological tissue seal 90, suchas pericardium tissue or other animal tissue used at both the locationof the bumper 80 to cover the internal foam layer 82, as well as to sealand cover the open stent structure 86 up to the location of an existingfabric layer 92 circumscribing the replacement heart valve 60. Thecombination of the existing fabric layer 92 on the stent valve 60 andthe seal layer 90 circumscribing the lower or outflow portion of thevalve 60 prevents blood flow from leaking past the valve 60 through thestent structure 86. Instead, the blood passes as it should through theleaflets 62, 64 of the replacement valve 60. As further shown in FIG.14A, the helical anchor 12 is preferably formed of spaced apart coils 22creating a gap 91 such as configured in any embodiment previouslydiscussed in connection with PCT Application Serial No.PCT/US2014/050525 the disclosure of which is hereby fully incorporatedby reference herein, or spaced apart or formed as otherwise desired. Asfurther described in PCT/US2014/050525, the helical anchor 12 isexpansible by the stent valve 60.

Referring to FIGS. 15A-15C, an initial portion of a procedure accordingto another illustrative embodiment is shown. In this figure, a sheath100 and delivery catheter 101 have been advanced through a peripheralvein into the right atrium 102 of the heart 40, across the atrial septum104, to the left atrium 106. A distal end 10 a of the delivery catheter101 is positioned in the left ventricle 108 by being directed throughthe native mitral valve 16. This delivery catheter 101 contains aself-expanding or stent mounted mitral prosthesis or replacement valve60 that is to be implanted at the location of the native mitral valve16. A super elastic or shape memory type material, such as Nitinol, istypically used to form the frame structure or body 66 of theself-expanding replacement valve 60, but other materials may be usedinstead. The frame or body 66 includes artificial valve leaflets 18, 20typically formed from tissue such as pericardial cow or pig tissue.Leaflets 18, 20 could instead be formed of other materials, such assynthetic or other biomaterials, e.g., materials derived from smallintestinal mucosa. As described further below, the delivery catheter 101also contains a helical anchor 12 and delivery system. The helicalanchor 12 may generally take the forms described herein or previouslydisclosed, for example, in PCT Application Serial Nos. PCT/US2014/050525and PCT/IB2013/000593. The disclosure of the PCT/IB2013/000593application is also incorporated by reference herein.

FIG. 15B illustrates the delivery catheter 101 inside the left ventricle108 with the distal tip 10 a just below the native mitral valve leaflets18, 20. The procedure has been initiated with exposure of the contentsof the delivery system.

FIG. 15C illustrates another portion of the procedure subsequent to FIG.15B and illustrating that the prosthetic or replacement mitral valve 60has been partially delivered through the distal end 10 a of the catheter101. The end of the replacement valve 60 that is positioned in the leftventricle 108 has arms 110 that wrap around the native mitral leaflets18, 20 and serve to anchor the replacement valve 60 firmly against themargins of the native mitral valve leaflets 18, 20. The arrows 112 showhow the arms 110 have wrapped around the lower margins of the nativemitral leaflets 18, 20 after the arms 110 have been extruded or deployedoutwardly from the delivery catheter 101. This replacement valve 60construction has been shown in the above-incorporated PCT ApplicationSerial No. PCT/IB2013/000593. These arms 110 will help prevent thereplacement valve 60 from dislodging upward into the left atrium 106when the replacement valve 60 is fully positioned, because the arms 110hook around the edges of the native mitral leaflets 18, 20. Multiplearms 110 are useful to provide a lower plane of attachment of the mitralvalve prosthesis 60 to the native mitral valve 16. The arms 110 may varyin length and in character and construction. It will be understood thata plurality of arms 110 is used with this embodiment, but only two arms110 are shown in these figures for purposes of illustration andsimplification. One of the arms 110 includes a loop 120 to direct orcontrol the helical anchor delivery catheter 10 that contains a helicalanchor 12. The anchor delivery catheter 10 has been preloaded into theloop 120 before the assembly was loaded into the delivery sheath 100.The arm with the loop 120 may be of heavier construction than the otherarms 110 and does not have to resemble the other arms 110. The arms 110have shape memory property such that when they are extruded or deployedoutwardly from the anchor catheter 10 they wrap around the native mitralleaflets 18, 20. The arm 110 with the loop 120 wraps around the nativemitral leaflets 18, 20 and the attached helical anchor delivery catheter10 is carried with it so that the chordae 24 and the native mitral valveleaflets 18, 20 are positioned inside the exposed end of the helicalanchor 12.

When the helical anchor 12 is advanced or extruded as is initially shownin FIG. 15C, it will encircle the chordae tendinae 24 so that all valveand chordae will be trapped inside the helical anchor 12. The loop 120swings the helical anchor delivery catheter 10 around the native mitralleaflets 18, 20 and above the chordae 24 into a preferred position underthe native mitral valve annulus 126. The arm 110 with the loop 120 mayhave a dual function of attachment of the valve 60 to the native leafletmargin and for guidance during delivery of the helical anchor 12. Theloop 120 may be sufficiently large to allow the helical anchor deliverycatheter 10 to pivot or swivel as the system is deployed. It isimportant for the helical anchor 12 to be extruded in a plane close toparallel to the underside of the native mitral valve 16. The helicalanchor delivery catheter 10 is also aimed or oriented to this plane bythe loop 120. The loop 120 may, in fact, be composed of a short tube(not shown) instead of a wire as shown. A tube would force the helicalanchor delivery catheter 10 into a favorable plane and orientation.Alternatively, the helical anchor delivery catheter 10 could besteerable in one of the manners known through steerable cathetertechnology.

Other mitral valve prosthesis or replacement valves may be used and havea wide range of attachment arms or wings, or stent structure, that wraparound the native mitral valve leaflets 18, 20. The arms or othersimilar structures in such prostheses could all be fitted with a loop120, or tube or other similar guidance structure, to perform similarfunctions as the loop 120 described immediately above. This functiongenerally relates to directing the delivery of the helical anchor 12.Furthermore, it is not necessary that a loop 120 directs the helicalanchor delivery. For example, a cell or opening of the replacement valvestent structure 86 could also perform the same function as the loop 120shown and described in these figures. A hook or a tube may also be usedin lieu of the illustrated loop 120. Any structure that can function todirect the helical anchor 12 around the native mitral valve leaflets 18,20 may be added to the prosthetic or replacement heart valve 60. Thestructure may be permanently fabricated as part of the replacement valve60 or may be temporary structure used only during the procedure. Forexample, a loop of suture (not shown) may be used to guide delivery of ahelical anchor 12 including any helical anchor delivery catheter 10associated therewith. After use of the suture, it may be withdrawn fromthe patient.

The arms 110 illustrated in these figures are quite narrow or slender.In practice, it may be more useful to have arms that are composed ofpairs or triplets of wires that are fused at the ends. The narrowterminal ends of the arms 110 facilitate the arms 110 passing betweenthe chordae tendinae 24 at their margins with the free edge of thenative mitral leaflets 18, 20 to allow the arms 110 to wrap around thenative leaflets 18, 20. The chordae 24 are closely packed in some areasand slender arms 110 will allow the arms 110 to pass between the chordaetendinae 24. Once the slender portion of the arms 110 pass, thickerportions of the arms 110 may move between the chordae 24 by spreadingthem apart. Therefore, an arm 110 that is slender or composed of asingle wire or fusion of wires at the tip and that is more robust orthicker closer to the main body of the prosthetic or replacement valve60, may be a desirable arrangement. The wires or arms 110 may also bemuch shorter than those shown in these illustrative figures. In theillustrated method, delivery of the helical anchor 12 may be started atany desired location and not necessarily at the commissure 14 of thenative mitral valve 16. For example, delivery may start in the middleportion of a native mitral leaflet 18 or 20. This would be advantageousfor the surgeon who would not have to precisely locate the commissure 14to begin the procedure, thereby greatly simplifying the procedure.

FIG. 15D illustrates the helical anchor 12 being delivered under thenative mitral leaflets 18, 20. The arrow 130 indicates the helicalanchor 12 being extruded from the helical anchor delivery catheter 10under the native mitral valve 16. Any number of coils or turns 22 of thehelical anchor 12 may be extruded depending on the particularconfiguration of helical anchor 12 being used in the procedure. Theinner diameter of the helical anchor 12 would preferentially be slightlyless than the outer diameter of the fully expanded mitral valveprosthesis 60 to promote firm engagement or anchoring of the replacementmitral valve 60. The helical anchor 12 may be composed of bare wire, ormay have coatings or coverings for various reasons such as thosedescribed in the above incorporated PCT applications. The partiallydelivered mitral valve prosthesis 60 serves an important function tocenter the delivery of the helical anchor 12. The mitral valveprosthesis or replacement valve 60 also provides a stable platform.

FIG. 15E illustrates that three turns 22 of the helical anchor 12 havebeen placed below the native mitral valve 16. These turns or coils 22have positioned the native mitral valve leaflets 18, 20 between thehelical anchor 12 and the prosthetic mitral valve 60 which is shown in aconfiguration about to be expanded. Once the replacement valve 60 isexpanded, this securely positions the replacement valve 60 and preventsleaks around the replacement valve 60 by sealing the native mitralleaflets 18, 20 to the prosthesis 60. The delivery sheath 101 for thereplacement valve 60 has been removed and when using a self-expandingvalve, the valve 60 would spring open upon removal of the deliverysheath 101. The arrows 132 indicate this process prior to itsoccurrence. In this figure, the replacement valve 60 is still in aclosed position to allow clear visualization of the turns or coils 22 ofthe helical anchor 12 beneath the native mitral valve 16. In thisconfiguration, there are three helical anchor coils 22 below the nativemitral valve 16, however, any number of coils 22 may be used instead.The coils 22 are positioned up against the underside of the mitral valveannulus 126 and leaflets 18, 20 to provide a solid buttress to fix thehelical anchor 12 in position and prevent movement into the left atrium106 when the powerful left ventricle 108 contracts. When the arms 110wrap around the helical anchor 12, the entire structure or assembly isstabilized in position. This embodiment provides a surgeon orinterventionalist a considerable amount of choice due to the fact thatthe anchor 12 may be delivered at the same time as the replacement valve60. Many shape memory framed prosthetic heart valves 60 may bere-sheathed. This means that during a procedure, the replacement valve60 may be partially advanced from a catheter or sheath 101 and testedfor its fit in the heart 40. If the surgeon or interventionalist is notsatisfied with the positioning of the replacement valve 60 before thefinal release of the replacement valve 60, this valve 60 may be pulledback into the sheath or catheter 101. Therefore, a prosthetic orreplacement valve 60 may be positioned initially with no helical anchor12 in place. If subsequent anchoring appeared strong and stable andthere was no evidence of movement or leakage, the valve 60 may bereleased. On the other hand, if the surgeon or interventionalist is notsatisfied, the valve 60 may be pulled back into the sheath 101. Thehelical anchor 12 may be implanted first, and then the valve 60 may beextruded from the delivery sheath 101. This would allow the user todecide on the clinical need for additional anchoring under the nativemitral valve 16.

FIG. 15F illustrates the fully implanted expandable replacement valve 60shown in proper position. The arms 110 have wrapped around the nativemitral valve leaflets 18, 20 to prevent the replacement valve 60 frommoving upward into the left atrium 106. The native mitral leaflets 18,20 are compressed under the arms 110 and a very solid mechanicalstructure and anchoring has been created to prevent the replacementvalve 60 from migrating to an undesirable position. The turns or coils22 of the helical anchor 12 also compress against the body 66 of theprosthetic or replacement valve 60 to position, orient and preventmovement of the replacement valve 60. Therefore, the helical anchor 12provides a friction attachment of the replacement valve 60 and serves toanchor the arms 110 that wrap around the helical anchor 12. The upperportion of the native mitral valve 16 is shown with a wider area thatsits inside the left atrium 106 to promote attachment to the wall of theleft atrium 106. However, the force moving the replacement valve 60 fromthe left atrium 106 toward the left ventricle 108 is low and thisportion of the replacement valve 60 may not be necessary and could beeliminated or reduced from a clinical prosthesis. The turns or coils 22of the helical anchor 12 are important because they can overcome a widevariety of variations in the lengths of the native mitral leaflets 18,20 from patient to patient and the length of the chordae tendinae 24 andthe attachment points of the chordae 24 in the left ventricle 108. Whena replacement valve 60 with arms 110 wrapping around the native mitralleaflets 18, 20 is used without any helical anchor 12 encircling underthe native leaflets 18, 20, the depth of fixation of the prostheticmitral valve 60 may vary around the perimeter of the implantedreplacement valve 60. For example, if the chordae tendinae 24 attachedto the middle part of the posterior leaflet 20 were very elongated orruptured, which is a common situation, the arms 110 may fail to wraparound and engage the native leaflet 20 at this location. Alternatively,there may be a very limited engagement along or at a much higher plane.This portion of the replacement valve 60 would be positioned higher,creating a skew in the replacement valve 60 so that the replacementvalve 60 would be positioned at an angle to the plane of inflowing bloodthrough the replacement valve 60. As the heart 40 beats, there is alarge load on the replacement valve 60 and it may begin to rock andshift. The heart 40 beats almost 100,000 times per day and after severaldays or weeks or months, the valve 60 may shift, move and/or dislodge.Also, if the leaflets 18, 20 and/or chordae 24 were very elongated,there may be no contact with the arms 110. This could result in a largeperivalvular leak due to lack of engagement of the replacement valve 60with the native mitral leaflets 18, 20. An anchor 12 under the nativemitral valve leaflets 18, 20 would compress native leaflet tissueagainst the replacement valve 60 and prevent this problem. The helicalanchor 12 would be positioned in one plane and prevent problems relatedto variations in patient anatomy.

In clinical practice, there are virtually limitless variations in thesize of the native mitral leaflets 18, 20, character of the nativemitral leaflets 18, 20, the chordal lengths and the attachment of thechordae 24 as well as the diameter of the mitral annulus 126. The use ofa helical anchor 12 or other anchor structure under the native leaflets18, 20 neutralizes many of these variables since the fixation point ofthe arms 110 may be brought to the lowest coil 22 of the helical anchor12. This position may also be determined in advance by selecting thenumber of coils 22 in the helical anchor 12 as well as the thickness ofthe coils 22 in the helical anchor 12 to match the turning point of thearms 110 on the lowest portion of the replacement valve 60. Thus, animportant feature of the helical anchor 12 delivered under the nativemitral annulus 126 is that it can create a common and predefined planefor anchoring the arms 110 of the replacement valve 60. In the situationdescribed above in which some of the chordae 24 are stretched, theattachment in this region of the replacement valve 60 could be to thehelical anchor 12. This would create a common plane for the lowest pointon the replacement valve 60. To ensure that the valve 60 anchors at acommon lowest plane throughout its perimeter, additional coils 22 may beadded to the helical anchor 12, or the diameter of the coils 22 may bemade larger. Additional options are, for example, waves or undulationsmay be added to the coils 22 of the helical anchor 12 to expand theoverall height of the helical anchor 12. The helical anchor 12 thereforeimproves stability of the replacement valve 60 by providing an anchoringpoint or location for the arms of the replacement valve 60 to wraparound while, at the same time, the helical anchor 12 can trap theperimeter of the replacement valve 60 along its length. The combinationof these features provides for increased stability to the replacementvalve 60 and can also seal the replacement valve 60 against the nativemitral valve 16 to prevent perivalvular leakage of blood flow. Asmentioned, the native mitral valve and heart structure of patients comesin many varieties and combinations. It is not practical for amanufacturer to make different lengths and depths of anchoring arms 110and for the user to deliver these products optimally into position foreach case. Rather, it is much more practical to adjust for thesevariations by placing a helical anchor 12 below the native mitral valve16 and using this to create a lowest plane for the arms 110 to anchoragainst. The delivery system for the helical anchor 12 may be anydelivery or deployment system, for example, described in theabove-incorporated PCT applications. It will be appreciated that suchdeployment methods and apparatus may be used to deliver the helicalanchor 12 such that the anchor 12 is positioned only below the nativemitral valve 16 as shown herein.

FIGS. 16A and 16B illustrate another embodiment in which a loop 120 isprovided at the end of an arm 110 on the replacement valve 60 thatguides the helical anchor delivery catheter 10. This loop 120 allows thedelivery catheter 10 to swivel as it is moved into position. In thisembodiment, the helical anchor delivery catheter 10 passes through thereplacement valve 60 or, in other words, within the replacement valvebody 66, however, it may be directed in manners other than that shown,and the helical anchor delivery catheter 10 may be used for additionalguidance along the path, such as by being steerable after being directedthrough the loop 120 farther than as shown in FIGS. 16A and 16B fordelivery of the helical anchor 12.

FIGS. 17A and 17B illustrate another embodiment in which a helicalanchor delivery tube 140 has been incorporated into the replacementvalve 60 instead of the helical anchor delivery catheter 10 previouslydescribed. In this embodiment, one arm of the replacement valve 60 is,in fact, the tube 140 that is loaded with and carries the helical anchor12. When the tubular arm 140 wraps around the native mitral valveleaflet (not shown), the helical anchor 12 is carried into the correctlocation and to the correct plane for delivery. Any structure on one ofthe arms 110 of the replacement valve 60 or any portion of thereplacement valve 60 that may guide the helical anchor 12 for deliverymay be used instead. In FIG. 17B, the helical anchor 12 has beenextruded from the tubular arm 140 for almost one complete rotation orturn. As previously described, multiple turns or coils 22 of the helicalanchor 12 may be deployed in this manner for ultimately securing thereplacement valve 60 at the native mitral valve 16 location generally asdescribed above. The main difference with this embodiment is that ahelical anchor delivery catheter 10 is not needed.

FIGS. 18A through 18C illustrate another embodiment for replacementvalve and helical anchor deployment and implantation. In this regard,the helical anchor delivery catheter 10 and the replacement valve 60 areessentially delivered side by side. FIG. 18A illustrates the helicalanchor delivery catheter 10 outside or extruded from the delivery sheath101 that also delivers the replacement valve 60. The helical anchordelivery catheter 10 passes through a loop 120 in one of the arms 110 ofthe replacement valve 60. The arrow 150 indicates that the helicalanchor 12 is about to be extruded from the end of the helical anchordelivery catheter 10. As shown in FIG. 18B, with the end of the helicalanchor delivery catheter 10 still in the loop 120, almost one full turnor coil 22 of the helical anchor 12 has been delivered under the nativemitral valve (not shown). FIG. 18C illustrates a further point duringthe implantation process in which about three turns or coils 22 of thehelical anchor 12 have been delivered under the plane 152 of the nativemitral valve 16. In this figure, the helical anchor delivery catheter 10and the sheath 101 delivering the replacement valve 60 have beenremoved. When the replacement valve 60 is formed with a self-expandingstent, the body 66 of the valve 60 will spring open when the deliverysheath 101 is removed. For purposes of clarity and illustration, thevalve 60 is still shown in a closed or unexpanded state simply forclarity. However, in general, the fully implanted system or assemblywill be similar to that shown in FIG. 15F.

FIGS. 19A and 19B illustrate another embodiment of a helical anchor 12.In this embodiment, the configuration of the helical anchor 12 in termsof the spacings and size of the coils 22 may vary. The cross-sectionalconstruction includes a fabric covering 160 which may, for example, bePET having a thickness of 0.008+/−0.002 inch, a weight of 2.12+−0.18ounce/yard² (72+/−6 grams/m²), a wale/inch of 40+/−5, courses/inch of90+/−10. A foam layer 162 may, for example, be 2 mm thick polyurethanesheet material. The foam may be attached to the fabric 160 using PTFEsuture with a light straight stitch. The fabric 160 and foam 162 maythen be folded around the center wire portion 22 a of the coils 22 ofthe helical anchor 12 and cross-stitched to the wire portion 22 a usingfiber suture.

FIG. 20 illustrates another system which may include the delivery of ahelical anchor 12 as set forth above and/or in the above incorporatedPCT applications. In accordance with this embodiment, however, anadditional tissue gathering device 170 is included in the deliverysystem. The device 170 delivers a temporary ring or loop 172 which cancorral or surround the bundles of chordae tendinae 24 into a smallerarea. This can facilitate easier placement of the helical anchor 12without entanglement or obstruction with the chordae tendinae 24. Also,shown in this figure is an introducer sheath 100, a delivery catheter101 as well as a steerable helical anchor delivery catheter 10 allgenerally as previously described.

FIGS. 21A and 21B illustrate another helical anchor device or assembly12. The assembly 12 is comprised of an upper or atrial helical anchorportion 180 as well as a lower or ventricular helical anchor portion182. These helical anchor portions 180, 182 are delivered simultaneouslyby extruding out of a helical anchor delivery catheter 10. The loweranchor portion 182 is delivered through the mitral valve 16 between thenative leaflets 18, 20. The upper and lower anchor portions 180, 182 maybe coupled together, for example, by a crimp joint 184. The upper anchorportion 180 is deployed above the native mitral valve 16 in the leftatrium 106 (FIG. 20). The upper and lower anchor portions 180, 182 maybe staggered such that the lower anchor portion 182 is initiallydirected into the commissure 14 and through the native mitral valve 16.As shown, the upper and lower helical anchor portions 180, 182 wind orrotate in opposite directions and then may be crimped together, as shownor may be precrimped or otherwise attached prior to loading the catheter10.

FIG. 22A and 22B illustrate another embodiment of a helical anchor andreplacement valve system similar to those discussed in connection withthe above-incorporated PCT Application Serial No. PCT/US2014/050525. Inthis embodiment, however, the configuration of the helical anchor 12 isshown to have a gap 200 between at least the upper coils 22 a and thenative mitral valve 16. As in the above incorporated PCT application,the helical anchor 12 includes an annular seal 202 of any desiredconfiguration extending lengthwise through or otherwise along the lengthof the anchor 12. In this embodiment, a panel or membrane seal 202 isshown extending downwardly from one of the coils 22 a and covering theportion of the stent mounted replacement valve 60 that would otherwisebe open due to the stent structure 86. The seal 202 therefore preventsleakage of blood past the replacement valve 60 through the open stentstructure 86. All other aspects of the assembly as shown in FIGS. 22Aand 22B are as described herein and may include any of the options orfeatures described herein or otherwise, for example, in theabove-incorporated PCT applications. The gap 200 is formed by a coilportion 22 b extending non-parallel to the adjacent coil portions 22 a,22 c.

FIGS. 23A and 23B illustrate another embodiment of a helical anchor 12,again similar to the above-incorporated PCT Application Serial No.PCT/US2014/050525. The difference between this embodiment and thesimilar embodiment shown in the above-incorporated PCT application isthat a gap 200 has been created between two of the middle coils 22 a, 22c of the anchor 12. These two figures illustrate the feature of thehelical anchor 12 in which the coils 22 will move or rotate as theexpandable anchor 12 is expanded by, for example, a balloon catheter210. As previously described, a gap 200 formed between adjacent coils 22a, 22 c may be used to ensure that native mitral tissue is not trappedor engaged by the adjacent coils 22 a, 22 c. The gap 200 is formed by acoil portion 22 b extending non-parallel to the adjacent coil portions22 a, 22 c.

While the present invention has been illustrated by a description ofpreferred embodiments and while these embodiments have been described insome detail, it is not the intention of the Applicants to restrict or inany way limit the scope of the appended claims to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. The various features and concepts of the inventionmay be used alone or in any combination depending on the needs andpreferences of the operator. This has been a description of the presentinvention, along with the preferred methods of practicing the presentinvention as currently known. However, the invention itself should onlybe defined by the appended claims.

What is claimed is:
 1. A system for replacing a native heart valve, thesystem comprising: an expansible helical anchor formed as multiple coilsadapted to support a heart valve prosthesis, at least one of the coilsnormally being at a first diameter, and being expandable to a second,larger diameter upon application of radial outward force from within thehelical anchor, wherein a gap is defined between adjacent coilssufficient to prevent engagement by at least one of the adjacent coilswith the native heart valve; an expansible heart valve prosthesiscapable of being delivered into the helical anchor and expanded insidethe multiple coils into engagement with the at least one coil to movethe at least one coil from the first diameter to the second diameterwhile securing the helical anchor and the heart valve prosthesistogether; and a seal on the helical anchor and configured to engage thehelical anchor and prevent blood leakage past the heart valve prosthesisafter implantation of the heart valve prosthesis in the helical anchor.2. The system of claim 1, wherein the helical anchor includes anothercoil that moves from a larger diameter to a smaller diameter as theheart valve prosthesis is expanded inside the multiple coils.
 3. Thesystem of claim 1, wherein the seal includes portions extending betweenadjacent coils for preventing blood leakage through the helical anchorand past the heart valve prosthesis.
 4. The system of claim 1, whereinthe seal further comprises a membrane or panel extending between atleast two coils of the helical anchor after implantation of the heartvalve prosthesis in the helical anchor.
 5. The system of claim 1,wherein the heart valve prosthesis includes a blood inflow end and ablood outflow end, at least one of the ends being unflared and generallycylindrical in shape.
 6. The system of claim 1, wherein the gap isformed by a coil portion of the helical anchor that extends non-parallelto adjacent coil portions of the helical anchor.
 7. The system of claim1, wherein the seal comprises a layer of foam.
 8. A method of implantingan expansible heart valve prosthesis in the heart of a patient,comprising: delivering an expansible anchor in the form of multiplecoils proximate the native heart valve, positioning the expansible heartvalve prosthesis within the multiple coils of the expansible anchor withthe expansible heart valve prosthesis and the expansible anchor inunexpanded states, expanding the expansible heart valve prosthesisinside the expansible anchor thereby expanding the expansible heartvalve prosthesis while securing the expansible heart valve prosthesisrelative to the expansible anchor; and carrying a seal on the anchor andextending between at least two adjacent coils for preventing bloodleakage through the anchor and past the heart valve prosthesis.
 9. Themethod of claim 8, wherein the anchor includes another coil portion thatmoves from a larger diameter to a smaller diameter while the expansibleheart valve prosthesis expands.
 10. The method of claim 8, wherein theseal further comprises a membrane or panel extending between at leasttwo coils of the anchor after implantation of the heart valve prosthesisin the anchor.
 11. The method of claim 8, wherein the seal furthercomprises a layer of foam.
 12. A system for replacing a native heartvalve, the system comprising: an anchor comprising multiple coils, atleast one of the coils normally being at a first diameter, and beingexpandable to a second, larger diameter upon application of radialoutward force from within the anchor; an expansible prosthetic heartvalve capable of being delivered into the anchor and expanded inside themultiple coils to move the at least one coil from the first diameter tothe second diameter while securing the anchor and the prosthetic heartvalve relative to each other; and a seal on the anchor comprising alayer of foam.
 13. The system of claim 12, wherein the anchor includes acoil portion that moves from a larger diameter to a smaller diameter asthe prosthetic heart valve is expanded inside the multiple coils. 14.The system of claim 12, wherein the seal includes portions extendingbetween adjacent coils for preventing blood leakage through the anchorand past the prosthetic heart valve.
 15. The system of claim 12, whereinthe seal further comprises a membrane or panel extending between atleast two coils of the anchor after implantation of the prosthetic heartvalve in the anchor.
 16. The system of claim 12, wherein the anchorcomprises a gap formed by a coil portion of the anchor that extendsnon-parallel to adjacent coil portions of the anchor.
 17. A system forreplacing a native heart valve, the system comprising: an anchorcomprising multiple coils, at least one of the coils normally being at afirst diameter, and being expandable to a second, larger diameter uponapplication of radial outward force from within the anchor; anexpansible prosthetic heart valve capable of being delivered into theanchor and expanded inside the multiple coils to move the at least onecoil from the first diameter to the second diameter while securing theanchor and the prosthetic heart valve relative to each other; and a sealon the anchor comprising a first layer of a first material and a secondlayer of a second material, the first material being a differentmaterial from the second material.
 18. The system of claim 17, whereinthe anchor includes a coil portion that moves from a larger diameter toa smaller diameter as the prosthetic heart valve is expanded inside themultiple coils.
 19. The system of claim 17, wherein the seal includesportions extending between adjacent coils for preventing blood leakagethrough the anchor and past the prosthetic heart valve.
 20. The systemof claim 17, wherein at least one of the first material and the secondmaterial is a foam material.
 21. The method of claim 17, wherein theanchor comprises an upper coiled anchor portion and a lower coiledanchor portion that each wind in opposite directions and are crimpedtogether.